Hello. My 5th grade son loves and collects gemstones. We are trying to figure out a Science Fair Project we can do about his collection. We are not sure how to proceed. Any advice would be very appreciated. Thank you.

Perhaps you can explore the relationship between various aspects of the gems, perhaps the relationship between color and density or color and weight? I'm not sure there is a definitive relationship, but that is always a possibility in science. You could also do research on the presence of gemstones in everyday objects and present this information as well, if that is an option for the project.